I have not yet discovered what the critical identification features are for placement in this family. The family was previously considered monospecific containing only Endromis versicolor, but several non-British species, formerly placed in Family: Bombycidae have now joined it. Dissection of E.versicolor reveals the following distinctive features: ​eyes glabrous; proboscis absent; labial palps present, hairy and appear to be composed of a single segment; maxillary palps rudimentary; hindwing lacks a frenulum and appears to lack any secure wing-coupling mechanism; hindtibia with a small apical pair of spurs (no mid-tibial pair); midtibia identical to hindtibia; foretibia with a very long epiphysis; valvae of male genitalia very heavily sclerotised.